The present invention relates to a device for turnable and slidable suspension of sheet-like elements, which are slidably supported by at least one rail and which are turnable about a pivot axis which is fixed relative to the sheet-like element. The device comprises a coupling member which is supported by said rail and has an elongate groove in essentially the same direction as the rail, and a coupling pin which is non-rotationally arranged on the sheet-like element so as to coincide with the pivot axis and which is slidable in the groove of the coupling member, the coupling pin and the coupling member being adapted to engage each other when the sheet-like element is turned relative to the rail.
A device of the type stated by way of introduction is known from Patent Specification WO 94/09238, in which a sliding element system, with guide wheels at the upper rail and a supporting wheel at the lower rail, for suspension of windowpanes is described. For the lower wheel to follow the correct path, a groove is formed in the lower rail. The forming of the lower wheel so as to have a rounded running tread engaging the edges of the groove and so as to be non-rotating relative to the windowpane results in the property that, when opening the window, the wheel is turned relative to the groove, which causes the wheel to rise. This motion is used to let a pin adjacent to the upper wheel enter a hole in the upper rail. When the pin is positioned in the hole and the lower wheel is arranged transversely in the rail, these two elements are locked relative to the longitudinal direction of the rails, which means that the windowpane cannot tilt when in the open position.
Without such locking, the windowpane would tilt by the upper part of the windowpane, owing to the weight of the windowpane which causes a moment relative to the suspension from the rails in the plane of the windowpane, sliding along the upper rail and the lower part of the windowpane sliding along the lower rail. This construction necessitates a large number of components, which makes the solution expensive. Moreover, when using this construction, there is a great risk that, when opening the windowpane by turning, the windowpane is turned upwards to a position in which the pin does not coincide with a hole, which results in a risk that the entire supporting structure is damaged or the windowpane is broken.
A further prior art device of the type stated by way of introduction is disclosed in WO 92/17673 and WO 93/08355. These two specifications disclose a device with a coupling member which is attached to an upper rail and chisel-like pin of rectangular cross-section, which is attached to the windowpane which is slidingly and turnably suspended between the upper rail and a lower rail. The coupling member has an elongate groove which is slightly broader than the smallest dimension of the chisel and extends through the coupling member in the longitudinal direction of the rail. A number of circular recesses are formed along the groove. Each of these circular recesses accommodates a turnable sleeve, which is formed with a groove which in a certain direction of rotation of the sleeve coincides with the groove of the coupling member. When the chisel is made to slide in the groove of the coupling member, with one of its short sides in the sliding direction, it also passes through the groove in each of the sleeves. The largest dimension of the chisel is slightly smaller than the diameter of the turning sleeve and the recess. Thus, when the chisel merely rests against the rail inside a turning sleeve, it is possible to open the windowpane by turning the same round the chisel and the axis that forms.
The number of components in this device is large, and narrow tolerances are necessary in respect of the mounting of the rails for the device to work in a satisfactory manner.
Also in connection with this construction, there is a great risk that the rail or the coupling device is damaged if the chisel is not arranged so as to coincide exactly with the turning sleeve. Great forces arise since the user utilises a great lever when grasping the windowpane and the coupling device has just extremely small levers since the profile of the rail must accommodate all the components.
A problem which is common to these two constructions thus is that there is a risk of breaking the rail or the coupling device by turning if the windowpane is not arranged in the correct position. Furthermore they necessitate narrow mounting tolerances and they are composed of a large number of components. As a result, it will be expensive to manufacture and mount the windowpanes and there is no space for absorbing settlements in the building structure or wear on the components included in the construction.
The object of the invention is to solve the problems described above and thus provide a device for slidable and turnable suspension of sheet-like elements, which is simple and robust.
This object is achieved by a device which is of the type described by way of introduction and characterized in that the groove of the coupling member has an inclined, lateral cam surface, that the coupling member has at least one essentially part-circular recess in the inclined lateral surface, the recess having a center axis which is essentially parallel to the pivot axis of the sheet-like element, that the coupling pin has a cylindrical surface with a center axis which is essentially parallel to the pivot axis of the sheet-like element, and that the cylindrical surface of the coupling pin has a beveled portion having a shape which is essentially the same as the cam shape of the lateral surface in the groove of the coupling member, the coupling member and the coupling pin being arranged to be relatively displaceable when the coupling pin is turned in such a manner that the inclined lateral surface in the groove and the beveled, portion of the coupling, pin abut against each other, and to engage each other when the cylindrical surface of the coupling pin, during turning of the sheet-like element, engages the part-circular recess of the coupling member.
By forming the coupling member and the coupling pin with cylindrical surfaces which are turned relative to each other about a common axis, the device will be very stable and robust. Only a small angle of turning is necessary before the coupling pin of the device engages the coupling member.
The inclined cam surface and the corresponding beveled portion make it possible to displace the cylindrical surfaces relative to each other in the direction along the rail when the coupling pin is correctly aligned.
The cutting edge forming between the inclined cam surface and the part-circular recess will have such a shape that the beveled portion of the coupling pin and, thus, the coupling pin are affected towards the center of the recess if one tries to turn the sheet-like element upwards without the coupling pin being perfectly aligned with a recess. As the coupling pin is being turned, with the beveled portion abutting against the cutting edge, a surface with an ever increasing circumference will abut against the cutting edge, which makes it necessary, from considerations of space, to move the coupling pin to a position where the entire circumference can be accommodated, i.e. closer and closer to a position where the center axes of the coupling pin and the recess coincide. This means that the device by itself takes an incorrect position of the sheet-like element at the stage of upwards turning into consideration and compensates for the same. This eliminates the risk that the rail or some other component is broken by turning.
Preferred embodiments are evident from the dependent claims.